An on-board unit may store information about a vehicle to which the on-board unit itself is attached and perform a process using the information. For example, in a case in which a fee for a toll road is set for each type of vehicle such as a large vehicle, an ordinary vehicle, and a two-wheeled vehicle, an on-board unit of a road billing system stores vehicle type information of the vehicle to which the on-hoard unit itself is attached, thereby enabling automatic billing in accordance with the type of vehicle.
If the on-board unit that stores information about a vehicle is used in another vehicle, a process may not be performed correctly. For example, if an on-board unit that stores information about a motorcycle is transferred from the motorcycle to an ordinary vehicle and used, a road billing system is likely to erroneously recognize the ordinary vehicle as the motorcycle and charge a fee for a motorcycle at a time of billing on a toll road.
Therefore, it is desirable to be able to detect that the on-board unit which stores information about a vehicle is used in another vehicle.
Several technologies for detecting fraud related to an on-board unit have been proposed. For example, a monitoring device for a fraudulent passing vehicle described in Patent Literature 1 includes a base station antenna for mobile communication, a camera that performs image capturing of a passing vehicle, an image processing device that identifies a number plate and vehicle type information of the vehicle from the image captured by the camera, and an antenna processing device that detects the fraudulent passing vehicle from a mismatch between vehicle data obtained by communicating with the vehicle via the base station antenna and the number plate and the vehicle type information of the vehicle identified by the image processing device.
In Patent Literature 1, in the monitoring device for a fraudulent passing vehicle, a vehicle using a toll road is prevented from using the toll road fraudulently by reloading an on-board unit.